Reliability and Convergent Validity of the National College Health Risk Behavior Survey Physical Activity Items

Abstract

This study examined the reliability and validity of the National College Health Risk Behavior Survey (NCHRBS) vigorous physical activity (VPA), moderate physical activity (MPA), flexibility (FLEX), and muscular strength and/or endurance (MSE) questions. Twenty college students completed the four items twice during the same day. During the next 7 days they wore an accelerometer and a pedometer during all waking hours. They also recorded their daily activity in a log. At the end of the week, subjects completed the NCHRBS physical activity items again. The intraclass correlation coefficients ranged from .94–.99 for the four items. The vigorous item was highly correlated with log VPA (r=.82) and number of days with ≥20 minutes of VPA from the accelerometer (r=.60). The flexibility item was moderately correlated (r=.57) and the muscular strength and/or endurance item was highly correlated (r=.89) with corresponding log activities. The moderate item was highly correlated with log MPA (r=.66) and number of days with ≥30 minutes of MPA from the accelerometer (r=.61). In conclusion, the NCHRBS physical activity items have excellent test-retest reliability and validity indices similar to other self-report physical activity questions.